1. Field of the Invention
This invention relates to a failure memory device which is capable of memorizing failure condition being monitored by electronic control units (ECU).
2. Discussion of Background
Remarkable development has been attained in recent years in equipping automobiles with more and more electronic appliances, as the result of which those electronic control units (ECU) equipped in those automobiles become corresponding to each and every function of the constituent parts in the automobile. As the example of these ECU's, there are those for electronically controlled suspension device, 4-speed automatic power transmission device (4-A/T), automatic cruising device, electronically controlled fuel injection device, and so forth. For each of these ECU's, the so-called "diagnosis signals (trouble-diagnosis output signals)", or error codes of these ECU's, are produced as an output through one signal line. The trouble-diagnosis output signals to be produced from n-number of electronic control units ECU-1 to ECU-n are collected into a diagnosis connector provided in, for example, a fuse box. Then, a connector to the side of the diagnosis tester (not shown in the drawing) is inserted into this diagnosis connector so as to light up by the trouble-diagnosis output signals those light-emitting-diodes provided in the diagnosis tester.
However, with the conventional diagnosis tester, it is only possible to light up the above-mentioned light-emitting-diodes, but it is not possible to store in advance those input signals from each of the sensors to be introduced into the ECU's, and to analyse the nature of various failures or troubles when they take place.